Sunk-type package structure

Abstract

A sunk-type package structure includes a substrate, an optical sensing chip, and a housing. The substrate has a cavity with a first depth. The optical sensing chip is disposed inside the cavity and electrically connected with the substrate. A surface of the optical sensing chip has a first sensing area for sensing light. The housing covers the substrate and the optical sensing chip. The housing has a light-permeable portion disposed above the first sensing area.

What is claimed is: 
     
         1 . A sunk-type package structure, comprising:
 a substrate, having a cavity with a first depth;   an optical sensing chip, disposed inside the cavity and electrically connected with the substrate, wherein a surface of the optical sensing chip has a first sensing area for sensing light; and   a housing, covering the substrate and the optical sensing chip and having a light-permeable portion disposed above the first sensing area.   
     
     
         2 . The sunk-type package structure according to  claim 1 , further comprising a metal film formed on inner walls and a bottom of the cavity, wherein the optical sensing chip is disposed on the metal film. 
     
     
         3 . The sunk-type package structure according to  claim 1 , further comprising:
 a grounding pad, disposed on the optical sensing chip and near the first sensing area; and   a light source chip, disposed on the grounding pad and configured to emit light, wherein the light source chip is electrically connected with the grounding pad.   
     
     
         4 . The sunk-type package structure according to  claim 3 , wherein the housing includes a shield wall, which is disposed between the first sensing area and the light source chip. 
     
     
         5 . The sunk-type package structure according to  claim 3 , wherein a distance between a central point of the light source chip and a central point of the first sensing area is greater than or equal to 0.8 mm. 
     
     
         6 . The sunk-type package structure according to  claim 2 , further comprising:
 a light source chip, disposed on the metal film and configured to emit light, wherein the housing includes a shield wall disposed between the optical sensing chip and the light source chip.   
     
     
         7 . The sunk-type package structure according to  claim 1 , wherein the surface of the optical sensing chip further has a second sensing area for sensing light, and the sunk-type package structure further comprises:
 a first polarization plate, covering the first sensing area and having a first polarization direction; and   a second polarization plate, covering the second sensing area and having a second polarization direction that is vertical to the first polarization direction;   wherein the light-permeable portion includes a quarter-wave plate disposed above the first polarization plate and the second polarization plate.   
     
     
         8 . The sunk-type package structure according to  claim 1 , wherein a distance between an edge of a solder mask of the substrate and an edge of the cavity is greater than or equal to 200 um; a distance between the edge of the cavity and an edge of the optical sensing chip is greater than or equal to 75 um; a distance between the edge of the cavity and an edge of the sunk-type package structure is greater than or equal to 100 um. 
     
     
         9 . The sunk-type package structure according to  claim 1 , wherein the substrate has a thickness of T, and the first depth is T/2±30 um. 
     
     
         10 . The sunk-type package structure according to  claim 1 , wherein the substrate is a coreless carrier plate. 
     
     
         11 . The sunk-type package structure according to  claim 1 , wherein a thickness of the optical sensing chip is smaller than or equal to the first depth.